The invention relates generally to electrical connectors, and more particularly, to a modular connector with compensation for crosstalk among multiple signal paths through the connector.
In electrical systems, there is increasing concern for preserving signal integrity as signal speed and bandwidth increase. One source of signal degradation is crosstalk between multiple signal paths. In the case of an electrical connector carrying multiple signals, crosstalk occurs when signals conducted over a first signal path are partly transferred by inductive or capacitive coupling into a second signal path. The transferred signals produce crosstalk in the second path that degrades the signal routed over the second path.
For example, a typical industry standard type RJ-45 communication connector includes four pairs of conductors defining four different signal paths. In conventional RJ-45 plug and jack connectors, all four pairs of conductors extend closely parallel to one another over a length of the connector body. Thus, signal crosstalk may be induced between and among different pairs of connector conductors. The amplitude of the crosstalk, or the degree of signal degradation, generally increases as the frequency increases. It is desirable to suppress or compensate for crosstalk, and ideally, the crosstalk compensation should be introduced as close as possible to the source of the crosstalk.
In the case of RJ-45 connectors, the plug design is controlled by industry standards which require it to contain a substantial amount of crosstalk. Therefore, efforts to counteract crosstalk are typically applied to the mating jack. In one approach, terminal contacts in the jack are formed with free ends that are deflected to contact a compensation coupling contact when a plug is mated with the jack. See, for example, U.S. Pat. No. 6,350,158. In general, the effectiveness of these measures is influenced by the proximity of the corrective measure to the main source of the crosstalk, e.g., the mating plug.